17 小时之前 · Different representations on 3D shapes have been used by machine learning models for CFD simulation, particularly the drag coefficient prediction. Song et al (Song et al., 2023) adopts a new 3D representation using stacked depth and normal renderings. Six single views, front, rear, top, bottom, right and left, are generated and integrated into ...

The drag coefficient is an adimensional number which defines the air resistance for a given shape. It is defined as the drag force (Fd) divided by dynamic pressure (which is 1/2 air density multiplied for the square of the speed v) and multiplied by the reference area A of the shape:

A collection of correlations for the drag coefficient (drag laws) can be found in the extensive technical literature available on particle-fluid interactions. Some of the most common and validated drag correlations for single particle (dilute flow) are implemented in the Rocky DEM-CFD coupling modules and apply to spherical and non-spherical ...

2020年1月15日 · In this work, we employed CFD-DEM simulations to study the behaviour of seven different drag models: three classic models (Wen-Yu, Gidaspow, Di Felice), three developed with Lattice-Boltzmann simulations (Rong, Beetstra, Koch-Hill), and one developed with Direct Numerical Simulations (Tenneti).

2012年3月20日 · A liquid–solid fluidization system was investigated with Computational Fluid Dynamics (CFD) by using a transient Eulerian-Eulerian model. The study focused on various drag models between the phases and how the results vary when simulating the system 2-dimensional or 3-dimensional. Also the grid dependencies to the results were investigated.

2023年9月1日 · The drag coefficient is a crucial concept in fluid dynamics that quantifies the resistance an object experiences when moving through a fluid. In the realm of Computational Fluid Dynamics (CFD) simulations, drag coefficient estimation plays a vital role in optimizing designs, reducing costs, and improving performance.

该模型是常用拖曳力模型中最早最著名的一个，也是各种cfd软件中的默认模型。 适用范围 ：所有流体-流体系统，最适合直径为2.5mm的球形气泡，但稳定性较差。

6 小时之前 · Blended-wing-body designs: Revolutionizing aircraft aerodynamics for reduced drag and improved fuel efficiency. Computational fluid dynamics (CFD): Simulating thousands of aerodynamic ...

Rastello et al. [5] 研究了紧密堆积气泡对气泡阻力的影响，并通过考虑单分散群中上升的气泡的局部气体滞留和相互作用提出了归一化的 C_D 关联式。 \begin {split}C_D (\chi)=&\frac {16} {Re_p}\left [\frac {1+8/15 (\chi-1)+0.015 (3G (\chi)-2)Re_p} {1+0.015Re_p}\\+\left [\frac8 {Re_p}+\frac12\left (1+\frac {3.315H (\chi)G (\chi)} {Re_p}\right) \right]^ {-1} \right] (1+\frac {0.3} {Ro^ {2.5}})\end {split}\tag {12}

1 天前 · (Yetkin et al. 2023) used CFD database to predict aerodynamic coefficients using AI. Machine learning (XGB, CatBoost, Bagging, Light-GBM, Random Forest, Gradient Boosting), deep learning (One Dimensional Convolutional Neural Network), and surrogate models were used. The aerodynamic coefficients predicted by these methods match reference CFD ...